This invention is directed to a method and apparatus for pneumatic spinning of yarn from natural- and synthetic fibres.
The hitherto known method of pneumatic spinning consists of introducing fibres entrained by air into the non-rotational spinning chamber where they are acted upon by air jets and are caused to rotate in response thereto. As a result of peripheral velocities generated in the section where the yarn is being formed, it is twisted by gathering of the fibres from a whirling fiberous ring whereupon the produced yarn is discharged from the chamber.
Prior art equipment using the above-mentioned method consists of the cylindrical, non-rotatable chamber, which at one end communicates with a source of vacuum, and is closed at the other end. A cylindrical insert incorporating concentric channel discharges the ready yarn. From the vacuum side, this chamber is provided with peripheral tangent ducts to supply air, and a fibre delivery zone.
The spinning process rate according to the prior art is proportional to the peripheral velocities within the zone where the fibre ring is being formed, in the spinning section. The formation of the field of the peripheral velocities, however, is counter-acted by the whirl core being developed in the chamber centre line, whereby this whirl core stabilizes on the insert lower surface, and in the chamber outlet.